CVE-2026-109399
CVE-2026-109399 · SWUpdate through 2026.05.1 CMS Signature Verification Bypass via Embedded Intermediates
This page contains facts from public vulnerability sources. Check the original advisory before updating.
SWUpdate through 2026.05.1 contains an improper certificate validation vulnerability in crypto/swupdate_cms_verify_openssl.c that trusts untrusted X.509 certificates embedded in CMS SignedData for chain building. Attackers holding a signing key from a sibling intermediate under the same root can embed that intermediate in the signature to install malicious updates.
CVSS 9.2 · Critical · EPSS 0.2% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
swupdate
- Versions
- ≥ 0, ≤ 2026.05.1: Affected (custom)
No fix published
swupdate Debian:12
- Versions
- 2022.12+dfsg-4
- 2022.12+dfsg-4+deb12u1
- 2022.12+dfsg-4+deb12u1~bpo11+1
- 2022.12+dfsg-4+deb12u2
- 2022.12+dfsg-4+deb12u3
- 2023.05+dfsg-1
- 2023.05+dfsg-2
- 2023.05+dfsg-2~bpo12+1
- 2023.05+dfsg-3
- 2023.05+dfsg-4
- 2023.05+dfsg-5
- 2023.05+dfsg-5~bpo12+1
- 2023.12+dfsg-1
- 2023.12+dfsg-1~bpo12+1
- 2023.12.1+dfsg-1
- 2023.12.1+dfsg-1~bpo12+1
- 2023.12.1+dfsg-2
- 2023.12.1+dfsg-2~bpo12+1
- 2024.05+dfsg-1
- 2024.05.2+dfsg-1
- 2024.05.2+dfsg-2
- 2024.05.2+dfsg-2~bpo12+1
- 2024.12+dfsg-1
- 2024.12+dfsg-2
- 2024.12+dfsg-2~bpo12+1
- 2024.12.1+dfsg-1
- 2024.12.1+dfsg-1~bpo12+1
- 2024.12.1+dfsg-2
- 2024.12.1+dfsg-3
- 2024.12.1+dfsg-3~bpo12+1
- 2025.05+dfsg-1
- 2025.05+dfsg-2
- 2025.05+dfsg-2~bpo13+1
- 2025.05+dfsg-3
- 2025.05+dfsg-3~bpo13+1
- 2025.12+dfsg-1
- 2025.12+dfsg-10
- 2025.12+dfsg-10~bpo13+1
- 2025.12+dfsg-10~bpo13+2
- 2025.12+dfsg-2
- 2025.12+dfsg-2~bpo13+1
- 2025.12+dfsg-3
- 2025.12+dfsg-4
- 2025.12+dfsg-5
- 2025.12+dfsg-6
- 2025.12+dfsg-7
- 2025.12+dfsg-7~bpo13+1
- 2025.12+dfsg-8
- 2025.12+dfsg-9
- 2026.05+dfsg-1
- 2026.05+dfsg-2
- 2026.05+dfsg-3
- 2026.05+dfsg-3~bpo13+1
- 2026.05+dfsg-4
- 2026.05.1+dfsg-1
- 2026.05.1+dfsg-1~bpo13+1
- 2026.05.1+git20261001+dfsg-1
- 2026.05.1+git20261001+dfsg-2
- 2026.05.1+git20261001+dfsg-2~bpo13+1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
swupdate Debian:14
- Versions
- 2024.12.1+dfsg-3
- 2025.05+dfsg-1
- 2025.05+dfsg-2
- 2025.05+dfsg-2~bpo13+1
- 2025.05+dfsg-3
- 2025.05+dfsg-3~bpo13+1
- 2025.12+dfsg-1
- 2025.12+dfsg-10
- 2025.12+dfsg-10~bpo13+1
- 2025.12+dfsg-10~bpo13+2
- 2025.12+dfsg-2
- 2025.12+dfsg-2~bpo13+1
- 2025.12+dfsg-3
- 2025.12+dfsg-4
- 2025.12+dfsg-5
- 2025.12+dfsg-6
- 2025.12+dfsg-7
- 2025.12+dfsg-7~bpo13+1
- 2025.12+dfsg-8
- 2025.12+dfsg-9
- Affected ranges
- ECOSYSTEM: < 2026.05+dfsg-1
Update to 2026.05+dfsg-1
swupdate Ubuntu:22.04:LTS
- Versions
- 2020.11-2
- 2021.04-1.1
- 2021.04-2
- 2021.04-2build1
- 2021.11-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
swupdate Ubuntu:24.04:LTS
- Versions
- 2023.05+dfsg-3
- 2023.05+dfsg-4
- 2023.05+dfsg-4build1
- 2023.05+dfsg-5
- 2023.12+dfsg-1
- 2023.12.1+dfsg-1ubuntu1
- 2023.12.1+dfsg-1ubuntu4
- 2023.12.1+dfsg-1ubuntu5
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
swupdate Ubuntu:26.10
- Versions
- 2025.12+dfsg-4ubuntu1
- 2026.05+dfsg-3ubuntu2
- 2026.05+dfsg-4ubuntu1
- 2026.05.1+dfsg-1ubuntu1
- 2026.05.1+git20261001+dfsg-1ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
swupdate Ubuntu:26.04:LTS
- Versions
- 2025.05+dfsg-2ubuntu1
- 2025.05+dfsg-3ubuntu1
- 2025.12+dfsg-1ubuntu1
- 2025.12+dfsg-2ubuntu1
- 2025.12+dfsg-3ubuntu1
- 2025.12+dfsg-4ubuntu1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
Original sources
- https://groups.google.com/g/swupdate/c/dsoMcGFnEns
- https://github.com/sbabic/swupdate/commit/e66c5640664a31668926a24c0c84b6b6570dc0d9
- https://github.com/sbabic/swupdate/blob/2026.05.1/crypto/swupdate_cms_verify_openssl.c
- https://github.com/sbabic/swupdate
- https://www.vulncheck.com/advisories/swupdate-through-2026.05.1-cms-signature-verification-bypass-via-embedded-intermediates
- https://nvd.nist.gov/vuln/detail/CVE-2026-109399